# US 2019/0357355 A1 · Metal-clad laminate, circuit board, and multilayer circuit board

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- Number: US 2019/0357355 A1
- Document ID: US20190357355A1
- Status: Published application
- Kind: A1
- Application number: 16/526,243
- Filed: 2019-07-30
- Published: 2019-11-21
- Earliest claimed: 2017-03-06
- Assignees: Murata Manufacturing Co., Ltd.
- Applicants: Murata Manufacturing Co., Ltd.
- Inventors: Kazuhiko Ohashi; Sunao Fukutake; Takeshi Eda
- Web page: https://patentgrep.com/patent/US20190357355A1

## CPC

- B32B 27/20: using fillers, pigments, thixotroping agents
- H05K 1/036: {Multilayers with layers of different types}
- B32B 3/266: {characterised by an apertured layer, the apertures going through the whole thickness of the layer, e.g. expanded metal, perforated layer, slit layer regular cells B32B3/12}
- B32B 7/12: using interposed adhesives or interposed materials with bonding properties
- B32B 15/082: comprising vinyl resins; comprising acrylic resins
- B32B 15/09: comprising polyesters
- B32B 15/092: comprising epoxy resins
- B32B 15/20: comprising aluminium or copper {(B32B15/016 and B32B15/017 take precedence)}
- B32B 27/36: comprising polyesters
- C08J 5/125: {Adhesives in organic diluents}
- C09J 125/08: Copolymers of styrene (C09J129/08, C09J135/06, C09J155/02 take precedence)
- C09J 153/02: Vinyl aromatic monomers and conjugated dienes
- C09J 153/025: {modified}
- C09J 163/00: Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins
- H05K 1/115: {Via connections; Lands around holes or via connections (H05K1/112 takes precedence)}
- H05K 1/181: associated with surface mounted components
- H05K 1/185: associated with components encapsulated in the insulating substrate of the PCBs; associated with components incorporated in internal layers of multilayer circuit boards
- H05K 3/386: {by the use of an organic polymeric bonding layer, e.g. adhesive}
- H05K 3/4623: {the circuit boards having internal via connections between two or more circuit layers before lamination, e.g. double-sided circuit boards (H05K3/462 takes precedence)}
- H05K 3/4626: {characterised by the insulating layers or materials (H05K3/4688 takes precedence)}
- B32B 2250/02: 2 layers
- B32B 2264/10: Inorganic particles
- B32B 2264/102: Oxide or hydroxide
- B32B 2264/104: Oxysalt, e.g. carbonate, sulfate, phosphate or nitrate particles
- B32B 2264/108: Carbon, e.g. graphite particles
- B32B 2305/55: Liquid crystals
- B32B 2307/202: Conductive
- B32B 2307/204: Di-electric
- B32B 2307/206: Insulating
- B32B 2307/302: Conductive
- B32B 2307/4026: within the layer by addition of a colorant, e.g. pigments, dyes
- B32B 2307/538: Roughness
- B32B 2307/714: Inert, i.e. inert to chemical degradation, corrosion
- B32B 2307/732: Dimensional properties
- B32B 2307/734: Dimensional stability
- B32B 2307/748: Releasability
- B32B 2457/08: PCBs, i.e. printed circuit boards
- C08J 2453/02: of vinyl aromatic monomers and conjugated dienes
- C08J 2463/00: Characterised by the use of epoxy resins; Derivatives of epoxy resins
- C08J 2463/02: Polyglycidyl ethers of bis-phenols
- C08J 2463/10: Epoxy resins modified by unsaturated compounds
- H05K 2201/0141: Liquid crystal polymer [LCP]
- H05K 2201/0195: Dielectric or adhesive layers comprising a plurality of layers, e.g. in a multilayer structure
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- C09J: ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES (preparation of glue or gelatine C09H)

## Abstract

A metal-clad laminate that includes a metal foil with low surface roughness and in which the adhesion strength between a liquid crystal polymer film and the metal foil is high, the low transmission loss in a high frequency region is low, and the problems associated with warpage and adhesive leakage are alleviated. The metal-clad laminate includes the liquid crystal polymer film, an adhesive layer, and the metal foil, with the adhesive layer and the metal foil stacked on one surface of the liquid crystal polymer film.

## Claims

### Claim 1

A metal-clad laminate comprising:
a liquid crystal polymer film;
an adhesive layer disposed on the liquid crystal polymer film, with the adhesive layer having:
a thickness of 0.5 μm or more and 4.0 μm or less,
a dynamic magnification of at least 1.15, and
a loss tangent of 0.16 or less at a strain of 0.06% under periodic strain at 1 Hz, and; and
a metal foil disposed on the adhesive layer and having a surface in contact with the adhesive layer having roughness height of 0.4 μm or less.

### Claim 2 (depends on 1)

The metal-clad laminate according to claim 1, wherein the adhesive layer has a relative permittivity of 3.0 or less and a dielectric dissipation factor of 0.008 or less.

### Claim 3 (depends on 1)

The metal-clad laminate according to claim 1, wherein the adhesive layer comprises a main agent and a curable resin.

### Claim 4 (depends on 3)

The metal-clad laminate according to claim 3, wherein the main agent is a carboxy group-containing styrene-based elastomer.

### Claim 5 (depends on 4)

The metal-clad laminate according to claim 4, wherein the curable resin is an epoxy resin.

### Claim 6 (depends on 1)

The metal-clad laminate according to claim 1, wherein the liquid crystal polymer film has a thickness of 5 μm or more and 130 μm or less.

### Claim 7 (depends on 1)

The metal-clad laminate according to claim 1, wherein the metal foil has a thickness of 5 μm or more and 40 μm or less.

### Claim 8

A circuit board comprising:
a metal-clad laminate that includes;
a liquid crystal polymer film;
an adhesive layer disposed on the liquid crystal polymer film, with the adhesive layer having:
a thickness of 0.5 μm or more and 4.0 μm or less,
a dynamic magnification of at least 1.15, and
a loss tangent of 0.16 or less at a strain of 0.06% under periodic strain at 1 Hz, and; and
a metal foil disposed on the adhesive layer and having a surface in contact with the adhesive layer having roughness height of 0.4 μm or less; and
a circuit disposed in the metal foil of the metal-clad laminate.

### Claim 9 (depends on 8)

A multilayer circuit board comprising two or more of the circuit boards according to claim 8, wherein the circuit boards are stacked on top of each other.

### Claim 10 (depends on 9)

The multilayer circuit board according to claim 9, comprising at least one via connecting the stacked circuits boards.

### Claim 11 (depends on 8)

The multilayer circuit board according to claim 8, further comprising an electronic device that is mounted on each circuit.

### Claim 12 (depends on 9)

The multilayer circuit board according to claim 9, further comprising an electronic device that is mounted on each circuit.

### Claim 13 (depends on 8)

The multilayer circuit board according to claim 8, wherein the adhesive layer has a relative permittivity of 3.0 or less and a dielectric dissipation factor of 0.008 or less.

### Claim 14 (depends on 8)

The multilayer circuit board according to claim 8, wherein the adhesive layer comprises a main agent and a curable resin, and the main agent is a carboxy group-containing styrene-based elastomer.

### Claim 15 (depends on 14)

The multilayer circuit board according to claim 14, wherein the curable resin is an epoxy resin.

### Claim 16 (depends on 8)

The multilayer circuit board according to claim 8, wherein the liquid crystal polymer film has a thickness of 5 μm or more and 130 μm or less.

### Claim 17 (depends on 8)

The multilayer circuit board according to claim 8, wherein the metal foil has a thickness of 5 μm or more and 40 μm or less.

### Claim 18

An electronic component comprising:
a multilayer circuit board, with each circuit board including:
a metal-clad laminate that includes a liquid crystal polymer film, an adhesive layer, and a metal foil stacked on the adhesive layer,
wherein the adhesive layer includes a thickness of 0.5 μm or more and 4.0 μm or less, a dynamic magnification of at least 1.15, and a loss tangent of 0.16 or less at a strain of 0.06% under periodic strain at 1 Hz,
wherein the metal foil has a surface in contact with the adhesive layer with roughness height of 0.4 or less, and
wherein a circuit is disposed in the metal foil of the metal-clad laminate; and
a mother board with the multilayer circuit board mounted on the mother board.

### Claim 19 (depends on 18)

The electronic component according to claim 18, wherein the multilayer circuit board comprises at least one via connecting the stacked circuits boards.

### Claim 20 (depends on 18)

The electronic component according to claim 18, wherein an electronic device is mounted on each circuit of each circuit board in the multilayer circuit board.